The objectives are to try out methods of probability estimation, both for categorized and continuous data, with application especially to medical diagnosis, and also to ecology, and to high-energy physics. These methods will probably be largely those already proposed by I.J. Good, but comparisons will be made with other methods especially those of regression. For these comparisons both known and artificial populations will be used for simulation of samples to which the various methods can be applied. More than one criterion will be used for making the comparison; for example, mean square deviation of the true from the inferred distribution, and also criteria given, for example, in my paper "What is the use of a distribution?".